It's been working for me since before the switchover date, so I reckon it's something to do with your implementation.
Viewing post in Google Analytics 4 Update Guide
I still struggle with setting it up propperly. I got my "data stream" created in GA4 for URL: https://szajnaworkshop.itch.io/. I have a G-XXXXXXXX code, which I paste into itchio settings "third-party analytics" tab. Is there anything more I should do? What am I missing?